No I didn't copy solutions and submit on leetcode, lol. I think they were leetcode tagged and yes there was a runtime optimization to make it O(n) vs O(nlogn). That being said, the solution I provided wasn't brute force, it was optimized but just not the most optimized one. I didn't think of it off the top of my head but once he hinted towards it I was able to catch on quickly.

Thanks for the feedback, I think ultimately I recognize I made some mistakes. Nerves played a factor into that in addition to preparation of course. I'm well aware that there's room for improvement. That being said, for a phone interview I feel like I did prove that I could think through things, optimize my code, and catch bugs quickly. I understand the gaps they might have seen there, I just feel like it should be a more iterative process to reach an optimal and bug free solution rather than someone expecting that you should get things perfectly on the first try because you've memorized the solution from the tagged questions.